US20220228312A1 - Lint filter clogging detection in a dryer appliance using compressor temperature and referigerant mass flow - Google Patents
Lint filter clogging detection in a dryer appliance using compressor temperature and referigerant mass flow Download PDFInfo
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- US20220228312A1 US20220228312A1 US17/154,569 US202117154569A US2022228312A1 US 20220228312 A1 US20220228312 A1 US 20220228312A1 US 202117154569 A US202117154569 A US 202117154569A US 2022228312 A1 US2022228312 A1 US 2022228312A1
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Images
Classifications
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- D06F58/32—Control of operations performed in domestic laundry dryers
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- B01D46/0084—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours provided with safety means
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- D06F58/02—Domestic laundry dryers having dryer drums rotating about a horizontal axis
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- D—TEXTILES; PAPER
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- D—TEXTILES; PAPER
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- D—TEXTILES; PAPER
- D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
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- D—TEXTILES; PAPER
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- D06F2105/62—Stopping or disabling machine operation
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- D—TEXTILES; PAPER
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- D—TEXTILES; PAPER
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- D—TEXTILES; PAPER
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- D06F58/32—Control of operations performed in domestic laundry dryers
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Definitions
- the subject matter of the present disclosure relates generally to dryer appliance for laundry and more particularly to the detection of lint filter clogging in a dryer appliance.
- a dryer appliance provides for drying wet articles of laundry usually after a washing process.
- the articles may include e.g., clothing, linens, and other items.
- the wet articles are placed into a compartment or drum through which relatively dry, heated air is passed in order to capture and remove moisture (e.g., water) from the articles.
- moisture e.g., water
- the moisture-laden air may be vented in order to remove moisture from the appliance.
- the air may be recirculated after being cooled, which causes the water vapor present to condense so that it may be removed.
- the circulated air is usually filtered in order to remove lint, which is an accumulation of textile fibers and other materials that may be released from the laundry articles during the drying process.
- lint is an accumulation of textile fibers and other materials that may be released from the laundry articles during the drying process.
- One or more such filters may be utilized in the dryer appliance. As the lint accumulates, the filter must be periodically cleaned. Some laundry articles e.g., may shed more lint during a drying cycle thereby loading the filter more quickly. The frequency of cleaning required depends upon several variables including the materials from which the laundry articles were created and the frequency of use of the appliance.
- the pressure drop of air passing through the filter also increases while the needed flow of drying air through the appliance decreases.
- This pressure drop may increase gradually or may occur more quickly.
- the pressure drop may increase over the course of several drying cycles if the user neglects to regularly clean the filter, or a particular high-lint-shedding laundry load may clog the filter during a drying cycle.
- residual lint may simply accumulate over time even though the filter is automatically cleaned or if the auto cleaning cycle is not entirely effective.
- the increased pressure drop is undesirable because the concomitant reduction in air flow leads to increased drying times and, therefore, lower energy efficiency.
- the reduced air flow can also lead to undesirable overheating of the inlet air to the drum.
- the reduced air flow may lead to overheating of the compressor, which can also undesirably heat the space where the appliance is located such as a laundry room of the user.
- a drying appliance equipped to detect the clogging of one or more lint filters would be useful.
- Such an appliance equipped to take one or more corrective actions once clogging to the lint filter is detected would be particularly useful.
- the present invention provides a method of operating an appliance used for drying a load of articles placed into a compartment of the appliance, the appliance having at least one lint filter and a heat pump system that includes a compressor and refrigerant circuit.
- the method includes beginning a drying cycle for the load of articles; determining when a steady state condition has been reached during the drying cycle for the load of articles; ascertaining whether a frequency of compressor temperature response exceeds a predetermined threshold value of compressor temperature response, and, if so, then detecting if a refrigerant mass flow rate is below a predetermined threshold value of refrigerant mass flow rate; and undertaking a corrective action if the refrigerant mass flow rate is below a predetermined threshold value of refrigerant mass flow rate.
- the present invention provides a laundry appliance.
- the appliance includes a cabinet and a drum located in the cabinet and defining a compartment for receipt of articles for drying during a drying cycle.
- the appliance also includes a lint filter and a heat pump system having a compressor within a refrigerant circuit.
- a controller is configured for beginning a drying cycle for the load of articles; determining when a steady state condition has been reached during the drying cycle for the load of articles; ascertaining whether a frequency of compressor temperature response exceeds a predetermined threshold value of compressor temperature response, and, if so, then detecting if a refrigerant mass flow rate is below a predetermined threshold value of refrigerant mass flow rate; and undertaking a corrective action if the refrigerant mass flow rate is below a predetermined threshold value of refrigerant mass flow rate.
- FIG. 1 provides a perspective view of a laundry appliance in accordance with exemplary embodiments of the present disclosure.
- FIG. 2 provides a perspective view of the exemplary laundry appliance of FIG. 1 with portions of a cabinet of the laundry appliance removed to reveal certain components of the laundry appliance.
- FIG. 3 provides a schematic diagram of an exemplary heat pump laundry appliance and a conditioning system thereof in accordance with exemplary embodiments of the present disclosure.
- FIG. 4 illustrates a plot of the volumetric air flow as a function of time during drying cycles of an exemplary appliance.
- FIG. 5 illustrates a plot of refrigerant mass flow rate as a function of time during drying cycles of an exemplary appliance.
- FIG. 6 illustrates plots of compressor shell temperature as a function of time for two different drying cycles of an exemplary appliance.
- FIG. 7 is a diagram of an exemplary method of operating an exemplary appliance of the present invention.
- FIGS. 8 and 9 depict plots of temperature and relative humidity as function of time for a drying cycle of an appliance.
- FIGS. 1 and 2 provide perspective views of a laundry appliance 10 according to exemplary embodiments of the present disclosure.
- Laundry appliance 10 is a dryer appliance for drying a load of articles in the illustrated embodiments and may also, in additional embodiments, include features for washing articles.
- laundry appliance 10 may also, or instead, be a combination laundry appliance.
- FIG. 1 provides a perspective view of dryer appliance 10
- FIG. 2 provides another perspective view of dryer appliance 10 with a portion of a housing or cabinet 12 of dryer appliance 10 removed in order to show certain components of dryer appliance 10 .
- dryer appliance 10 defines a vertical direction V, a lateral direction L, and a transverse direction T, each of which is mutually perpendicular such that an orthogonal coordinate system is defined. While described in the context of a specific embodiment of dryer appliance 10 , using the teachings disclosed herein it will be understood that dryer appliance 10 is provided by way of example only. Other laundry appliances having different appearances and different features may also be utilized with the present subject matter as well. For instance, in some embodiments, laundry appliance 10 can be a combination washing machine/dryer appliance or a condensing laundry drying appliance.
- Cabinet 12 includes a front panel 14 , a rear panel 16 , a pair of side panels 18 and 20 spaced apart from each other by front and rear panels 14 and 16 along the lateral direction L, a bottom panel 22 , and a top cover 24 .
- Cabinet 12 defines an interior volume 29 .
- a drum, or container 26 is mounted for rotation about a substantially horizontal axis within the interior volume 29 of cabinet 12 .
- Drum 26 defines a compartment or chamber 25 for receipt of articles for tumbling and/or drying.
- Drum 26 extends between a front portion 37 and a back portion 38 , e.g., along the transverse direction T.
- Drum 26 also includes a back or rear wall 34 , e.g., at back portion 38 of drum 26 .
- a supply duct 41 may be mounted to rear wall 34 .
- Supply duct 41 receives heated air that has been heated by a conditioning system 40 and provides the heated air to drum 26 via one or more holes defined in rear wall 34 .
- the terms “clothing” or “articles” includes but need not be limited to fabrics, textiles, garments, linens, papers, or other items from which the extraction of moisture is desirable.
- the term “load” or “laundry load” refers to the combination of clothing or articles that may be washed together in a washing machine or dried together in a dryer appliance (e.g., clothes dryer) and may include a mixture of different or similar articles of clothing of different or similar types and kinds of fabrics, textiles, garments and linens within a particular laundering process.
- a motor 31 is provided to rotate drum 26 about the horizontal axis, e.g., via a pulley and a belt (not pictured).
- Drum 26 is generally cylindrical in shape.
- Drum 26 has an outer cylindrical wall 28 and a front flange or wall 30 that defines an opening 32 of drum 26 , e.g., at front portion 37 of drum 26 , for loading and unloading of articles into and out of chamber 25 of drum 26 .
- Drum 26 includes a plurality of lifters or baffles 27 that extend into chamber 25 to lift articles therein and then allow such articles to tumble back to a bottom of drum 26 as drum 26 rotates.
- Baffles 27 may be mounted to drum 26 such that baffles 27 rotate with drum 26 during operation of dryer appliance 10 .
- Rear wall 34 of drum 26 is rotatably supported within cabinet 12 by a suitable bearing.
- Rear wall 34 can be fixed or can be rotatable.
- Rear wall 34 may include, for instance, a plurality of holes that receive hot air that has been heated by a conditioning system 40 , e.g., a heat pump or refrigerant-based conditioning system as will be described further below.
- a conditioning system 40 e.g., a heat pump or refrigerant-based conditioning system as will be described further below.
- Moisture laden, heated air is drawn from drum 26 by an air handler, such as a blower fan 48 , which generates a negative air pressure within drum 26 .
- the moisture laden heated air passes through a duct 44 enclosing screen filter 46 , which traps lint particles.
- Other filters or placements of filter 46 may also be utilized in the scope of the invention and claims that follow.
- dryer appliance 10 is a heat pump dryer appliance and thus conditioning system 40 may be or include a heat pump system or sealed refrigerant circuit 80 , as described in more detail below with reference to FIG. 3 .
- Heated air (with a lower moisture content than was received from drum 26 ), exits conditioning system 40 and returns to drum 26 by duct 41 . After the clothing articles have been dried, they are removed from the drum 26 via opening 32 .
- a door 33 provides for closing or accessing drum 26 through opening 32 .
- one or more selector inputs 70 may be provided or mounted on a cabinet 12 (e.g., on a backsplash 71 ) and are communicatively coupled with (e.g., electrically coupled or coupled through a wireless network band) at least one processing device or controller 56 .
- Controller 56 may also be communicatively coupled with various operational components of dryer appliance 10 , such as motor 31 , blower 48 , components of conditioning system 40 , and various sensors (e.g., temperature, relative humidity, and weight) as will be further described.
- signals generated in controller 56 direct operation of motor 31 , blower 48 , or conditioning system 40 in response user inputs to selector inputs 70 .
- processing device may refer to one or more microprocessors, microcontroller, ASICS, or semiconductor devices and is not restricted necessarily to a single element.
- the controller 56 may be programmed to operate dryer appliance 10 by executing instructions stored in memory (e.g., non-transitory media).
- the controller 56 may include, or be associated with, one or more memory elements such as RAM, ROM, or electrically erasable, programmable read only memory (EEPROM).
- the instructions may be software or any set of instructions that when executed by the processing device, cause the processing device to perform operations.
- controller 56 as disclosed herein is capable of and may be operable to perform any methods or associated method steps as disclosed herein.
- methods disclosed herein may be embodied in programming instructions stored in the memory and executed by the controller 56 .
- FIG. 3 provides a schematic view of laundry appliance 10 and depicts an air conditioning system 40 in more detail.
- laundry appliance 10 is a heat pump dryer appliance and thus conditioning system 40 includes a sealed heat pump system 80 .
- the conditioning system 40 illustrated in FIG. 3 and described herein may also be provided in, for example, a combination washing machine/dryer appliance.
- the present invention is not limited to laundry appliance having a sealed system and may be used e.g., with a system that vents moisture laden air out of appliance 10 .
- sealed system 80 includes various operational components, which can be encased or located within a machinery compartment of dryer appliance 10 . Generally, the operational components are operable to execute a vapor compression cycle for heating and cooling process air passing through conditioning system 40 .
- the operational components of sealed system 80 include an evaporator 82 , a compressor 84 , a condenser 86 , and one or more expansion devices 88 connected in series along a refrigerant circuit or line 90 .
- a cooling fan 89 may be provided to remove excess heat from the compressor 84 .
- an auxiliary condenser may be provided to supplement condenser 86 .
- the expansion device 88 is an expansion valve, such as an electronic expansion valve.
- Refrigerant line 90 is charged with a working fluid, which in this example is a refrigerant.
- Sealed system 80 depicted in FIG. 3 is provided by way of example only. Thus, it is within the scope of the present subject matter for other configurations of the sealed system to be used as well.
- the expansion device 88 may also, or instead, include a capillary tube.
- sealed system 80 may include additional components, e.g., at least one additional evaporator, compressor, expansion device, and/or condenser.
- sealed system 80 may include two (2) evaporators.
- the sealed system 80 may optionally include one or more sensors for measuring characteristics and operating conditions of the sealed system 80 .
- the sealed system 80 may include a suction line temperature sensor 94 , e.g., upstream of the compressor 84 .
- the sealed system 80 may include an evaporator inlet temperature sensor 96 positioned at an inlet of the evaporator 82 and configured to measure a temperature of the refrigerant at the inlet of the evaporator 82 .
- Sealed system 80 can include a temperature sensor 91 for measuring a temperature of compressor 84 or, more particularly, for measuring the shell temperature of compressor 84 .
- Sealed system 80 may also include a refrigerant flow rate sensor 83 for measuring the mass flow rate of refrigerant in circuit 90 .
- Sensor 83 may be placed e.g., immediately upstream or downstream of compressor 84 . Other locations may be used as well.
- one or more laundry articles LA may be placed within the chamber 25 of drum 26 .
- Hot dry air DA is supplied to chamber 25 via duct 41 .
- the hot dry air DA enters chamber 25 of drum via a drum inlet 52 defined by drum 26 , e.g., the plurality of holes defined in rear wall 34 of drum 26 as shown in FIG. 2 .
- the hot dry air DA provided to chamber 25 causes moisture (e.g., water) within laundry articles LA to evaporate. Accordingly, the air within chamber 25 increases in water content and exits chamber 25 as warm moisture laden air MLA.
- the warm moisture laden air MLA exits chamber 25 through a drum outlet 54 defined by drum 26 and flows into duct 44 .
- blower fan 48 moves the warm moisture laden air MLA, as well as the air more generally, through a process air flow path 58 defined by drum 26 , conditioning system 40 , and the duct system 60 .
- blower fan 48 is operable to move air through or along the process air flow path 58 .
- Duct system 60 includes all ducts that provide fluid communication (e.g., airflow communication) between drum outlet 54 and conditioning system 40 and between conditioning system 40 and drum inlet 52 .
- blower fan 48 is shown positioned between drum 26 and conditioning system 40 along duct 44 , it will be appreciated that blower fan 48 can be positioned in other suitable positions or locations along duct system 60 .
- the warm moisture laden air MLA flows into or across evaporator 82 of the conditioning system 40 .
- the temperature of the air is reduced through heat exchange with refrigerant that is vaporized within, for example, coils or tubing of evaporator 82 .
- This vaporization process absorbs both the sensible and the latent heat from the moisture laden air MLA—thereby reducing its temperature.
- moisture in the air is condensed and such condensate (e.g., water) may be drained from conditioning system 40 , e.g., using a drain line 92 , which is also depicted in FIG. 2 .
- Air passing over evaporator 82 becomes cooler than when it exited drum 26 at drum outlet 54 .
- cool air CA (cool relative to hot dry air DA and moisture laden air MLA) flowing downstream of evaporator 82 is subsequently caused to flow across condenser 86 , e.g., across coils or tubing thereof, which condenses refrigerant therein.
- the refrigerant enters condenser 86 in a gaseous state at a relatively high temperature compared to the cool air CA from evaporator 82 .
- dryer appliance 10 can have a much greater efficiency than traditional clothes dryers where all or most of the warm, moisture laden air MLA is exhausted to the environment.
- conditioning system 40 of dryer appliance 10 optionally includes an electric heater 102 positioned to provide heat to process air flowing along the process air flow path 58 , e.g., as shown in FIG. 3 .
- Electrical heater 102 can receive electrical power (e.g., from a power source) and can generate heat based at least in part on the received electrical power. The generated heat can be imparted to the process air flowing along the process air flow path 58 .
- compressor 84 pressurizes refrigerant (i.e., increases the pressure of the refrigerant) passing therethrough and generally motivates refrigerant through the sealed refrigerant circuit or refrigerant line 90 of conditioning system 40 .
- Compressor 84 may be communicatively coupled with controller 56 (communication lines not shown in FIG. 3 ).
- Refrigerant is supplied from the evaporator 82 to compressor 84 in a low pressure gas phase.
- the pressurization of the refrigerant within compressor 84 increases the temperature of the refrigerant.
- the compressed refrigerant is fed from compressor 84 to condenser 86 through refrigerant line 90 .
- the refrigerant is cooled and its temperature is lowered as heat is transferred to the air for supply to chamber 25 of drum 26 .
- the refrigerant Upon exiting condenser 86 , the refrigerant is fed through refrigerant line 90 to expansion valve 88 .
- Expansion valve 88 lowers the pressure of the refrigerant and controls the amount of refrigerant that is allowed to enter the evaporator 82 .
- the flow of liquid refrigerant into evaporator 82 is limited by expansion valve 88 in order to keep the pressure low and allow expansion of the refrigerant back into the gas phase in evaporator 82 .
- the evaporation of the refrigerant in evaporator 82 converts the refrigerant from its liquid-dominated phase to a gas phase while cooling and drying the moisture laden air MLA received from chamber 25 of drum 26 .
- dryer appliance 10 is depicted and described herein as a heat pump dryer appliance, in at least some embodiments, dryer appliance 10 can be a combination washer/dryer appliance as previously stated.
- the electronic expansion valve 88 can be operable to adjust a pressure of the refrigerant flowing along sealed system 80 .
- controller 56 may be configured to cause the electronic expansion valve 88 to adjust the pressure of the refrigerant flowing along the sealed system 80 .
- the electronic expansion valve 88 can be moved from a first position to a second position which is a closed position or an intermediate position (e.g., not fully open or fully closed) which is closer to the closed position than the first position. This can increase the pressure on the high side of sealed system 80 and decrease the pressure on the low side of sealed system 80 .
- the temperature of the refrigerant increases on the high side of sealed system 80 and the temperature of the refrigerant decreases on the low side of sealed system 80 . That is, adjustment of the electronic expansion valve can drive higher temperatures in condenser 86 and can lower the temperature of the evaporator 82 .
- adjustment of the electronic expansion valve 88 can maintain a constant superheat in the sealed system 80 and in particular a constant level of superheat into the compressor 84 , such as to avoid liquid refrigerant reaching the compressor 84 .
- the controller 56 may be configured to automatically adjust the electronic expansion valve 88 to maintain a constant degree of superheat into the compressor 84 .
- the electronic expansion valve 88 may be closed (or partially closed, e.g., moved to an intermediate position which is closer to the closed position than a prior position) to restrict the flow of refrigerant in the sealed system 80 .
- the degree of superheat in the sealed system 80 and therefore the dryness of the laundry articles LA may be determined based on the position of the electronic expansion valve 88 .
- the laundry appliance 10 may include a position sensor or other expansion valve position tracking system which may be used to determine the position of the electronic expansion valve 88 and thereby determine or detect dryness of the laundry articles LA based on the position of the electronic expansion valve 88 .
- appliance 10 may include one or more lint filters 46 and 110 to collect lint during drying operations.
- lint filter 46 is readily accessible by a user of the appliance. As such, lint filter 46 should be manually cleaned by removal of the filter, pulling or wiping away accumulated lint, and then replacing the filter 46 for subsequent drying cycles.
- appliance 10 may include one or more of an auto-cleaning lint filter 110 that is automatically cleaned at certain times as part of the operation of appliance 10 .
- Each of these filters 46 and 110 is placed into the path 58 of air flow through appliance 10 and includes a screen, mesh, other material to capture lint in the air flow.
- the location of lint filters in appliance 10 as shown in FIG. 3 is provided by way of example only, and other locations may be used as well.
- appliance 10 may include temperature sensors and relative humidity sensors that provide temperature (e.g., dry bulb temperature) and humidity measurements to controller 56 from certain locations in the air flow along path 58 during a drying cycle. More particularly, appliance 10 includes a temperature sensor 104 and a relative humidity sensor 105 placed at the outlet 54 of drum 26 (having compartment 25 for receipt of a load of articles for drying) in order to measure the temperature and relative humidity of the air exiting drum 26 . Such air is received from compartment 25 and may be MLA or moisture laden air, particularly in the earlier time period of a drying cycle of wet laundry articles.
- temperature sensor 104 and relative humidity sensor 105 are downstream of drum 26 and upstream of evaporator 82 . Based on their location relative to drum 26 and the direction of air flow, temperature sensor 104 and relative humidity sensor 105 may also be referred to herein as the drum outlet air temperature sensor 104 and drum outlet air relative humidity sensor 105 .
- Appliance 10 also includes a temperature sensor 106 and a relative humidity sensor 107 placed upstream of the drum 26 and at the outlet 87 of condenser 86 to measure the temperature and relative humidity of the after treatment by condenser 86 and before entering drum 26 .
- a temperature sensor 106 and a relative humidity sensor 107 placed upstream of the drum 26 and at the outlet 87 of condenser 86 to measure the temperature and relative humidity of the after treatment by condenser 86 and before entering drum 26 .
- Such air is supplied to compartment 25 and may be DA or relatively dry air from which water vapor has been removed as previously described.
- temperature sensor 106 and relative humidity sensor 107 may also be referred to herein as the condenser air outlet temperature sensor 106 and the condenser air outlet relative humidity sensor 107 .
- appliance 10 may include another placement of a temperature sensor and/or relative humidity sensor for measurements of air that is suppled to compartment 25 —placement that is downstream of condenser 86 and located just before entering drum 26 .
- appliance 10 may include a temperature sensor 108 and relative humidity sensor 109 placed at the inlet 52 of drum 26 . Based on their location relative to drum 26 and the direction of air flow, temperature sensor 108 and relative humidity sensor 109 may also be referred to herein as the drum inlet air temperature sensor 108 and drum inlet air relative humidity sensor 109 .
- Appliance 10 may also include means for determining the average moisture extraction rate (MER) from a load of laundry articles place in the compartment 25 of drum 26 during a drying cycle.
- the average moisture extraction rate or MER will be understood as the average rate of removal of moisture from articles in drum 26 by the air circulated therethrough during a drying cycle.
- appliance 10 may include a load sensor 110 on drum 26 . Load sensor can measure the weight w of laundry articles place in drum 26 at certain times t over the course of a drying cycle and provide this information to controller 56 . As moisture is removed from the laundry articles during the drying cycle, the weight of laundry articles in drum 26 will decrease. This is illustrated in FIG.
- Controller 56 can calculate an average MER by dividing the change in weight of the laundry articles by the elapsed time during which such weight changed occurred, as represented by Equation 1:
- the average MER may, for example, be expressed as pounds of water per minute, kilograms per second, or other mass per time units that may be used as well. Notably, as shown in FIG. 4 , the average MER (e.g., the slope of curve 103 w) becomes relatively constant once steady state conditions are reached.
- appliance 10 may use a flow meter 112 that measures the volumetric flow of condensate from drain line 92 and provides the same to controller 56 .
- condensate from evaporator 82 may be collected in a reservoir 116 and a pressure sensor or float 114 would measure the amount of condensate collected over a given time interval or determine when a predetermined amount of condensate has been collected in reservoir 116 and provide such information to controller 56 .
- a pressure sensor or float 114 would measure the amount of condensate collected over a given time interval or determine when a predetermined amount of condensate has been collected in reservoir 116 and provide such information to controller 56 .
- FIG. 4 illustrates a plot during a drying cycle of the volumetric air flow rate in cubic feet per minute (CFM) through air flow path 58 .
- Plot 800 represents a lint filter that was about 25 percent blocked whereas plot 802 represents a lint filter that was about 75 percent blocked (the percentages were determined relative to the desired unblocked airflow, which was considered to be 100 percent).
- the volumetric air flow rate is higher for the less clogged filter represented by plot 800 , and the volumetric air flow rate decreases over the time t of the drying cycle operation as lint accumulates.
- compressor temperature response can include one or more of a variety of actions depending upon the design of appliance 10 .
- compressor temperature response or CTR means the action appliance 10 undertakes in an effort to lower the temperature of compressor 84 .
- the temperature of a compressor may be measured at the compressor's shell, which is simply a temperature measurement at an exterior wall or shell of the compressor.
- compressor temperature response or CTR may include appliance 10 (e.g., controller 56 ) operating compressor 84 at a lower speed to maintain the superheated state and the inlet air temperature to drum 26 .
- the lower compressor speed means the mass flow rate of refrigerant (as measured by e.g., meter 83 ) through refrigerant circuit 90 will decrease.
- FIG. 5 provides a plot of refrigerant mass flow rate over time as measured e.g., by refrigerant mass flow rate sensor 83 .
- Plot 900 represents appliance 10 having 25 percent filter blockage whereas plot 902 is for appliance 10 having a 75 percent filter blockage (the percentage being determined with respect to no lint present (0 percent) and total blockage (100 percent).
- the mass flow rate of refrigerant in either case first reaches a steady state condition during a drying cycle. Thereafter, the mass flow rate of refrigerant is significantly less for plot 902 where the lint filter(s) of appliance 10 is significantly more clogged.
- the difference in plots 900 and 902 is particularly evident around the 45 to 50 minute mark one the mass flow rate has stabilized.
- compressor temperature response or CTR may include controller 56 activating an auxiliary condenser (connected in parallel or series with condenser 86 ) in order to maintain the superheated state and the inlet air temperature to drum 26 .
- the compressor temperature response or CTR may include controller 56 activating a cooling fan 89 for compressor 84 in order to maintain the superheated state and the inlet air temperature to drum 26 .
- FIG. 6 provides plots of shell temperature of compressor 84 over time as measured by e.g., temperature sensor 91 .
- Plot 1000 is for appliance 10 having 25 percent filter blockage whereas plot 1002 is for appliance 10 having a 75 percent filter blockage (the percentage being determined with respect to no lint present (0 percent) and total blockage (100 percent).
- the compressor shell temperature fluctuates as e.g., cooling fan 89 is cycled on and off and/or as auxiliary condenser is employed in an effort to regulate the shell temperature of compressor 84 .
- the frequency of the temperature regulation increases during a given drying cycle as lint accumulates in the filters(s), and the frequency of the temperature regulation is higher for the filter that is more clogged (plot 1002 ).
- the frequency of the temperature regulation by cooling fan 89 is about 50 percent higher when the filter(s) are 75 percent blocked as opposed to 25 percent blocked.
- An appliance 10 with a variable speed compressor 84 may also be equipped to utilize an auxiliary condenser or cooling fan as an alternative, or in addition to, compressor speed control for purposes of compressor temperature response or CTR.
- the present invention utilizes the compressor temperature response or CTR to determine the condition of the one or more lint filters in air flow path 58 . Based on the frequency of the compressor temperature regulation responses or CTRs, one or more actions may be undertaken by controller 56 . Referring to FIG. 7 , an exemplary method of 200 operating appliance 10 will now be described. Using the teachings disclosed herein, one of ordinary skill in the art will understand that other methods within the scope of the invention and claims that follow may be applied as well.
- determining steady state conditions may be important so that changes in the compressor temperature and/or mass flow rate of attributed to the accumulation of lint or clogging of the filter instead of being affected by transient changes that occur before appliance 10 reaches steady state.
- a variety of different techniques may be used to determine whether appliance 10 has reached steady state conditions.
- FIG. 8 depicts the temperature measurements 108 T from drum inlet air temperature sensor 108 and temperature measurements 104 T from drum outlet air temperature sensor 104 .
- FIG. 9 depicts the relative humidity (RH) measurements 109 RH from drum inlet air relative humidity sensor 109 and relative humidity (RH) measurements 105 RH from drum outlet air relative humidity sensor 105 .
- RH relative humidity
- temperature measurements 108 T from drum inlet air temperature sensor 108 changed rapidly during the first approximately 20 minutes of the drying cycle.
- the relative humidity measurements 109 RH from drum inlet air relative humidity sensor 109 also changed rapidly during the first approximately 10 minutes of the drying cycle.
- controller 56 may be configured to simply delay a predetermined period of time t initial after appliance 10 has been operating before proceeding to use compressor temperature response or CTR to determine the condition of the one or more lint filters in air flow path 58 .
- t initial might be preset as 20 minutes, after which in step 202 the controller 56 proceeds under the assumption of steady-state conditions. Other time periods for t initial may be used as well.
- controller 56 would determine whether the rate of change (ROC) of the temperature measurements 108 T , relative humidity measurements 109 RH , or both, has fallen below certain predetermined threshold values before proceeding to use compressor temperature response or CTR to determine the condition of the one or more lint filters in air flow path 58 .
- rate of change or ROC means the change in a measured value of a certain interval of time. For example, as indicative of a steady state condition being reached, controller 56 might monitor the temperature, relative humidity, or both, of air supplied to compartment or drum 26 to determine when the rate of change has reached or dropped below a predetermined threshold value, ROC THR .
- controller 56 may monitor temperature measurements 108 T and determine that a steady condition in drum 26 has not been reached until the rate of change (ROC) for temperature measurements 108 T is less than an ROC THR-T of 5 degrees per minute, less than 3 degrees per minute, or less than 1 degree per minute. Other values for ROC THR may be used as well.
- ROC rate of change
- controller 56 may monitor relative humidity measurements 109 RH and determine that a steady condition in drum 26 has not been reached until the rate of change (ROC) for relative humidity measurements 109 RH is less than an ROC THR-RH of 10 percent per minute, less than 5 percent per minute, or less than 1 percent per minute. Other values for ROC THR may be used as well.
- controller 56 might monitor both temperature and relative humidity measurements until the ROC for both the temperature measurements 108 T and relative humidity measurements 109 RH are each below certain predetermined threshold values, ROC THR .
- controller 56 might also use measurements from sensors 106 and 107 in addition to, or instead of, measurements from sensors 108 and 109 .
- controller 56 might also use measurements from refrigerant mass flow rate sensor 83 to determine that steady state conditions have been reached before proceeding to use compressor temperature response or CTR to determine the condition of the one or more lint filters in air flow path 58 . Accordingly, controller 56 might monitor the rate of change (ROC) for mass flow rate measurements and determine that steady conditions have not been reached until the ROC for the mass flow rate measurements is less than an ROC THR-MF of 10 percent per minute, less than 5 percent per minute, or less than 1 percent per minute. Other values for ROC THR-MF may be used as well.
- controller 56 ascertains whether the frequency of the CTRs (CTR F ) is at, or exceeds, a predetermined frequency threshold (CTR F-THR ) as an indicator of the conditions of lint filters 46 and/or 110 .
- CTR F the frequency of the CTRs
- CTR F-THR a predetermined frequency threshold
- CTR F-THR might be a fixed value such as CTR F-THR ⁇ 5 CTRs per hour or CTR F-THR ⁇ 10 CTRs per hour. Other values may be used as well.
- controller 56 might determine CTR F-THR has been reached based on a predetermined amount of increase in the frequency of CTRs after reaching steady state conditions. For example, controller 56 might determine CTR F-THR has been reached if the frequency of CTRs increases by more than 50 percent.
- controller 56 might determine CTR F-THR has been reached if the frequency of CTRs increases by more than 50 percent.
- appliance 10 e.g., controller 56 if appliance 10 (e.g., controller 56 ) ascertains that the frequency of CTRs or CTR F-THR has met or exceeds a certain predetermined frequency threshold (CTR F-THR ), then in step 208 appliance 10 proceeds to detect if the refrigerant mass flow rate (RMF), as may be measured by mass flow rate sensor 83 , is at or below a certain predetermined threshold value (RMF THR ). If so, then appliance 10 can undertake one or more corrective actions.
- RMF refrigerant mass flow rate
- appliance 10 can provide a notification to the user that one or more filters need to be cleaned.
- appliance 10 may skip step 208 and proceed directly to undertaking one or more corrective actions such as providing a notification to the user as in step 210 .
- Such alerts or notifications may be a visual and/or audible signal at the end of the previous drying cycle, could be provided when the user is about to initiate another drying cycle, or a combination thereof.
- appliance 10 may stop the current drying cycle of appliance 10 .
- appliance 10 may provide a notification to the user regarding a lint filter to indicate e.g., that such filter should be cleaned and/or stop operation of appliance 10 .
- appliance 10 may undertake an automated cleaning cycle of one or more lint filters.
- appliance 10 may be equipped with an oversized lint filter 46 that does need to be cleaned with every drying cycle.
- appliance 10 and particularly controller 56 may be configured to estimate when lint filter cleaning will be needed depending on variables such as load types and sizes.
- the degradation of the filter 46 can be correlated to the degree of filter loading for various load types and sizes, which can be determined based on user selection and load size determination as previously described.
- appliance 10 can alert the user that one or more lint filters or e.g., lint filter 46 should be cleaned.
- the process 200 described in FIG. 7 may be provided as a back-up to such estimations.
- CTR F-THR and/or RMF THR may include a first set of predetermined values based on a lint filter that is only at e.g., 75 percent clogged so that the corrective action of appliance 10 includes providing the user with a notification that the lint filter should be cleaned while continuing to allow operation of appliance 10 .
- a second set of values for CTR F-THR and/or RMF THR (indicative of e.g., 90 percent clogging of the lint filter) might be used to initiate a subsequent corrective action where a drying cycle of appliance 10 is terminated until the lint filter can be cleaned.
- controller 56 can provide an alert or notification to the user that the lint filter should be cleaned before starting another drying cycle, but controller 56 would only prevent another drying cycle if the second set of values for CTR F-THR and/or RMF THR has been reached.
- FIG. 7 is exemplary and representative only. Using the description provided herein, one of ordinary skill in the art will understand that other steps may also be used within the scope of the invention and claims that follow. The order of certain steps may be changed and operations described or claimed as a single step herein may actually be executed in multiple steps or operations.
- the invention includes an appliance having one or more controllers, microprocessors and/or other elements configured to operate a drying appliance as previously described. Also, while exemplary aspects of the invention have been described using English units (e.g., in the equations above), such is by way of example only and one of skill in the art will understand that e.g., the International System of Units (SI) may be used as well.
- SI International System of Units
Abstract
Description
- The subject matter of the present disclosure relates generally to dryer appliance for laundry and more particularly to the detection of lint filter clogging in a dryer appliance.
- Generally, a dryer appliance provides for drying wet articles of laundry usually after a washing process. The articles may include e.g., clothing, linens, and other items. The wet articles are placed into a compartment or drum through which relatively dry, heated air is passed in order to capture and remove moisture (e.g., water) from the articles. Depending on the type of dryer, the moisture-laden air may be vented in order to remove moisture from the appliance. Alternatively, the air may be recirculated after being cooled, which causes the water vapor present to condense so that it may be removed.
- The circulated air is usually filtered in order to remove lint, which is an accumulation of textile fibers and other materials that may be released from the laundry articles during the drying process. One or more such filters may be utilized in the dryer appliance. As the lint accumulates, the filter must be periodically cleaned. Some laundry articles e.g., may shed more lint during a drying cycle thereby loading the filter more quickly. The frequency of cleaning required depends upon several variables including the materials from which the laundry articles were created and the frequency of use of the appliance.
- As the amount of lint in the filter increases, the pressure drop of air passing through the filter also increases while the needed flow of drying air through the appliance decreases. This pressure drop may increase gradually or may occur more quickly. For example, the pressure drop may increase over the course of several drying cycles if the user neglects to regularly clean the filter, or a particular high-lint-shedding laundry load may clog the filter during a drying cycle. In appliances having an auto-cleaning filter, residual lint may simply accumulate over time even though the filter is automatically cleaned or if the auto cleaning cycle is not entirely effective.
- Regardless, the increased pressure drop is undesirable because the concomitant reduction in air flow leads to increased drying times and, therefore, lower energy efficiency. The reduced air flow can also lead to undesirable overheating of the inlet air to the drum. For a dryer that uses a heat pump cycle, the reduced air flow may lead to overheating of the compressor, which can also undesirably heat the space where the appliance is located such as a laundry room of the user.
- Conventional systems for detecting whether a lint filter needs cleaning have shown limited effectiveness. Such are sometimes based primarily on temperature measurements and can lack sensitivity to gradual accumulations in the filter.
- Accordingly, a drying appliance equipped to detect the clogging of one or more lint filters would be useful. Such an appliance equipped to take one or more corrective actions once clogging to the lint filter is detected would be particularly useful.
- Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.
- In a first exemplary aspect, the present invention provides a method of operating an appliance used for drying a load of articles placed into a compartment of the appliance, the appliance having at least one lint filter and a heat pump system that includes a compressor and refrigerant circuit. The method includes beginning a drying cycle for the load of articles; determining when a steady state condition has been reached during the drying cycle for the load of articles; ascertaining whether a frequency of compressor temperature response exceeds a predetermined threshold value of compressor temperature response, and, if so, then detecting if a refrigerant mass flow rate is below a predetermined threshold value of refrigerant mass flow rate; and undertaking a corrective action if the refrigerant mass flow rate is below a predetermined threshold value of refrigerant mass flow rate.
- In another exemplary aspect, the present invention provides a laundry appliance. The appliance includes a cabinet and a drum located in the cabinet and defining a compartment for receipt of articles for drying during a drying cycle. The appliance also includes a lint filter and a heat pump system having a compressor within a refrigerant circuit. A controller is configured for beginning a drying cycle for the load of articles; determining when a steady state condition has been reached during the drying cycle for the load of articles; ascertaining whether a frequency of compressor temperature response exceeds a predetermined threshold value of compressor temperature response, and, if so, then detecting if a refrigerant mass flow rate is below a predetermined threshold value of refrigerant mass flow rate; and undertaking a corrective action if the refrigerant mass flow rate is below a predetermined threshold value of refrigerant mass flow rate.
- These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
- A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
-
FIG. 1 provides a perspective view of a laundry appliance in accordance with exemplary embodiments of the present disclosure. -
FIG. 2 provides a perspective view of the exemplary laundry appliance ofFIG. 1 with portions of a cabinet of the laundry appliance removed to reveal certain components of the laundry appliance. -
FIG. 3 provides a schematic diagram of an exemplary heat pump laundry appliance and a conditioning system thereof in accordance with exemplary embodiments of the present disclosure. -
FIG. 4 illustrates a plot of the volumetric air flow as a function of time during drying cycles of an exemplary appliance. -
FIG. 5 illustrates a plot of refrigerant mass flow rate as a function of time during drying cycles of an exemplary appliance. -
FIG. 6 illustrates plots of compressor shell temperature as a function of time for two different drying cycles of an exemplary appliance. -
FIG. 7 is a diagram of an exemplary method of operating an exemplary appliance of the present invention. -
FIGS. 8 and 9 depict plots of temperature and relative humidity as function of time for a drying cycle of an appliance. - Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
-
FIGS. 1 and 2 provide perspective views of alaundry appliance 10 according to exemplary embodiments of the present disclosure.Laundry appliance 10 is a dryer appliance for drying a load of articles in the illustrated embodiments and may also, in additional embodiments, include features for washing articles. For example,laundry appliance 10 may also, or instead, be a combination laundry appliance. In particular,FIG. 1 provides a perspective view ofdryer appliance 10 andFIG. 2 provides another perspective view ofdryer appliance 10 with a portion of a housing orcabinet 12 ofdryer appliance 10 removed in order to show certain components ofdryer appliance 10. - As depicted,
dryer appliance 10 defines a vertical direction V, a lateral direction L, and a transverse direction T, each of which is mutually perpendicular such that an orthogonal coordinate system is defined. While described in the context of a specific embodiment ofdryer appliance 10, using the teachings disclosed herein it will be understood thatdryer appliance 10 is provided by way of example only. Other laundry appliances having different appearances and different features may also be utilized with the present subject matter as well. For instance, in some embodiments,laundry appliance 10 can be a combination washing machine/dryer appliance or a condensing laundry drying appliance. -
Cabinet 12 includes afront panel 14, arear panel 16, a pair ofside panels rear panels bottom panel 22, and atop cover 24.Cabinet 12 defines aninterior volume 29. A drum, orcontainer 26 is mounted for rotation about a substantially horizontal axis within theinterior volume 29 ofcabinet 12.Drum 26 defines a compartment orchamber 25 for receipt of articles for tumbling and/or drying.Drum 26 extends between afront portion 37 and aback portion 38, e.g., along the transverse direction T. Drum 26 also includes a back orrear wall 34, e.g., atback portion 38 ofdrum 26. Asupply duct 41 may be mounted torear wall 34.Supply duct 41 receives heated air that has been heated by aconditioning system 40 and provides the heated air todrum 26 via one or more holes defined inrear wall 34. - As used herein, the terms “clothing” or “articles” includes but need not be limited to fabrics, textiles, garments, linens, papers, or other items from which the extraction of moisture is desirable. Furthermore, the term “load” or “laundry load” refers to the combination of clothing or articles that may be washed together in a washing machine or dried together in a dryer appliance (e.g., clothes dryer) and may include a mixture of different or similar articles of clothing of different or similar types and kinds of fabrics, textiles, garments and linens within a particular laundering process.
- In some embodiments, a
motor 31 is provided to rotatedrum 26 about the horizontal axis, e.g., via a pulley and a belt (not pictured).Drum 26 is generally cylindrical in shape.Drum 26 has an outercylindrical wall 28 and a front flange orwall 30 that defines anopening 32 ofdrum 26, e.g., atfront portion 37 ofdrum 26, for loading and unloading of articles into and out ofchamber 25 ofdrum 26.Drum 26 includes a plurality of lifters or baffles 27 that extend intochamber 25 to lift articles therein and then allow such articles to tumble back to a bottom ofdrum 26 asdrum 26 rotates. Baffles 27 may be mounted to drum 26 such that baffles 27 rotate withdrum 26 during operation ofdryer appliance 10. -
Rear wall 34 ofdrum 26 is rotatably supported withincabinet 12 by a suitable bearing.Rear wall 34 can be fixed or can be rotatable.Rear wall 34 may include, for instance, a plurality of holes that receive hot air that has been heated by aconditioning system 40, e.g., a heat pump or refrigerant-based conditioning system as will be described further below. Moisture laden, heated air is drawn fromdrum 26 by an air handler, such as ablower fan 48, which generates a negative air pressure withindrum 26. The moisture laden heated air passes through aduct 44enclosing screen filter 46, which traps lint particles. Other filters or placements offilter 46 may also be utilized in the scope of the invention and claims that follow. - As the air passes from
blower fan 48, it enters aduct 50 and then is passed intoconditioning system 40. In some embodiments,dryer appliance 10 is a heat pump dryer appliance and thusconditioning system 40 may be or include a heat pump system or sealedrefrigerant circuit 80, as described in more detail below with reference toFIG. 3 . Heated air (with a lower moisture content than was received from drum 26), exitsconditioning system 40 and returns to drum 26 byduct 41. After the clothing articles have been dried, they are removed from thedrum 26 viaopening 32. Adoor 33 provides for closing or accessingdrum 26 throughopening 32. - In some embodiments, one or
more selector inputs 70, such as knobs, buttons, touchscreen interfaces, etc., may be provided or mounted on a cabinet 12 (e.g., on a backsplash 71) and are communicatively coupled with (e.g., electrically coupled or coupled through a wireless network band) at least one processing device orcontroller 56.Controller 56 may also be communicatively coupled with various operational components ofdryer appliance 10, such asmotor 31,blower 48, components ofconditioning system 40, and various sensors (e.g., temperature, relative humidity, and weight) as will be further described. In turn, signals generated incontroller 56 direct operation ofmotor 31,blower 48, orconditioning system 40 in response user inputs toselector inputs 70. As used herein, “processing device” or “controller” may refer to one or more microprocessors, microcontroller, ASICS, or semiconductor devices and is not restricted necessarily to a single element. Thecontroller 56 may be programmed to operatedryer appliance 10 by executing instructions stored in memory (e.g., non-transitory media). Thecontroller 56 may include, or be associated with, one or more memory elements such as RAM, ROM, or electrically erasable, programmable read only memory (EEPROM). For example, the instructions may be software or any set of instructions that when executed by the processing device, cause the processing device to perform operations. It should be noted thatcontroller 56 as disclosed herein is capable of and may be operable to perform any methods or associated method steps as disclosed herein. For example, in some embodiments, methods disclosed herein may be embodied in programming instructions stored in the memory and executed by thecontroller 56. -
FIG. 3 provides a schematic view oflaundry appliance 10 and depicts anair conditioning system 40 in more detail. For this exemplary embodiment,laundry appliance 10 is a heat pump dryer appliance and thusconditioning system 40 includes a sealedheat pump system 80. In additional embodiments, theconditioning system 40 illustrated inFIG. 3 and described herein may also be provided in, for example, a combination washing machine/dryer appliance. In other embodiments, the present invention is not limited to laundry appliance having a sealed system and may be used e.g., with a system that vents moisture laden air out ofappliance 10. - Continuing with
FIG. 3 , sealedsystem 80 includes various operational components, which can be encased or located within a machinery compartment ofdryer appliance 10. Generally, the operational components are operable to execute a vapor compression cycle for heating and cooling process air passing throughconditioning system 40. The operational components of sealedsystem 80 include anevaporator 82, acompressor 84, acondenser 86, and one ormore expansion devices 88 connected in series along a refrigerant circuit orline 90. A coolingfan 89 may be provided to remove excess heat from thecompressor 84. Alternatively, or in addition thereto, an auxiliary condenser may be provided to supplementcondenser 86. In the illustrated embodiments, theexpansion device 88 is an expansion valve, such as an electronic expansion valve.Refrigerant line 90 is charged with a working fluid, which in this example is a refrigerant.Sealed system 80 depicted inFIG. 3 is provided by way of example only. Thus, it is within the scope of the present subject matter for other configurations of the sealed system to be used as well. For example, in some embodiments, theexpansion device 88 may also, or instead, include a capillary tube. As will be understood by those skilled in the art, sealedsystem 80 may include additional components, e.g., at least one additional evaporator, compressor, expansion device, and/or condenser. As an example, sealedsystem 80 may include two (2) evaporators. - In some embodiments, the sealed
system 80 may optionally include one or more sensors for measuring characteristics and operating conditions of the sealedsystem 80. For example, the sealedsystem 80 may include a suctionline temperature sensor 94, e.g., upstream of thecompressor 84. As another example, the sealedsystem 80 may include an evaporatorinlet temperature sensor 96 positioned at an inlet of theevaporator 82 and configured to measure a temperature of the refrigerant at the inlet of theevaporator 82.Sealed system 80 can include atemperature sensor 91 for measuring a temperature ofcompressor 84 or, more particularly, for measuring the shell temperature ofcompressor 84.Sealed system 80 may also include a refrigerantflow rate sensor 83 for measuring the mass flow rate of refrigerant incircuit 90.Sensor 83 may be placed e.g., immediately upstream or downstream ofcompressor 84. Other locations may be used as well. - In performing a drying and/or tumbling cycle, one or more laundry articles LA may be placed within the
chamber 25 ofdrum 26. Hot dry air DA is supplied tochamber 25 viaduct 41. The hot dry air DA enterschamber 25 of drum via adrum inlet 52 defined bydrum 26, e.g., the plurality of holes defined inrear wall 34 ofdrum 26 as shown inFIG. 2 . The hot dry air DA provided tochamber 25 causes moisture (e.g., water) within laundry articles LA to evaporate. Accordingly, the air withinchamber 25 increases in water content and exitschamber 25 as warm moisture laden air MLA. The warm moisture laden air MLA exitschamber 25 through adrum outlet 54 defined bydrum 26 and flows intoduct 44. - After exiting
chamber 25 ofdrum 26, the warm moisture laden air MLA flows downstream toconditioning system 40.Blower fan 48 moves the warm moisture laden air MLA, as well as the air more generally, through a processair flow path 58 defined bydrum 26,conditioning system 40, and theduct system 60. Thus, generally,blower fan 48 is operable to move air through or along the processair flow path 58.Duct system 60 includes all ducts that provide fluid communication (e.g., airflow communication) betweendrum outlet 54 andconditioning system 40 and betweenconditioning system 40 anddrum inlet 52. Althoughblower fan 48 is shown positioned betweendrum 26 andconditioning system 40 alongduct 44, it will be appreciated thatblower fan 48 can be positioned in other suitable positions or locations alongduct system 60. - As further depicted in
FIG. 3 , the warm moisture laden air MLA flows into or acrossevaporator 82 of theconditioning system 40. As the moisture laden air MLA passes acrossevaporator 82, the temperature of the air is reduced through heat exchange with refrigerant that is vaporized within, for example, coils or tubing ofevaporator 82. This vaporization process absorbs both the sensible and the latent heat from the moisture laden air MLA—thereby reducing its temperature. As a result, moisture in the air is condensed and such condensate (e.g., water) may be drained fromconditioning system 40, e.g., using adrain line 92, which is also depicted inFIG. 2 . - Air passing over
evaporator 82 becomes cooler than when it exiteddrum 26 atdrum outlet 54. As shown inFIG. 3 , cool air CA (cool relative to hot dry air DA and moisture laden air MLA) flowing downstream ofevaporator 82 is subsequently caused to flow acrosscondenser 86, e.g., across coils or tubing thereof, which condenses refrigerant therein. The refrigerant enterscondenser 86 in a gaseous state at a relatively high temperature compared to the cool air CA fromevaporator 82. As a result, heat energy is transferred to the cool air CA at thecondenser 86, thereby elevating its temperature and providing warm dry air DA for resupply to drum 26 ofdryer appliance 10 throughinlet 52. The warm dry air DA passes over and around laundry articles LA within thechamber 25 of thedrum 26, such that warm moisture laden air MLA is generated, as mentioned above. Because the air is recycled throughdrum 26 andconditioning system 40,dryer appliance 10 can have a much greater efficiency than traditional clothes dryers where all or most of the warm, moisture laden air MLA is exhausted to the environment. - In some embodiments,
conditioning system 40 ofdryer appliance 10 optionally includes anelectric heater 102 positioned to provide heat to process air flowing along the processair flow path 58, e.g., as shown inFIG. 3 .Electrical heater 102 can receive electrical power (e.g., from a power source) and can generate heat based at least in part on the received electrical power. The generated heat can be imparted to the process air flowing along the processair flow path 58. - With respect to sealed
system 80,compressor 84 pressurizes refrigerant (i.e., increases the pressure of the refrigerant) passing therethrough and generally motivates refrigerant through the sealed refrigerant circuit orrefrigerant line 90 ofconditioning system 40.Compressor 84 may be communicatively coupled with controller 56 (communication lines not shown inFIG. 3 ). Refrigerant is supplied from theevaporator 82 tocompressor 84 in a low pressure gas phase. The pressurization of the refrigerant withincompressor 84 increases the temperature of the refrigerant. The compressed refrigerant is fed fromcompressor 84 tocondenser 86 throughrefrigerant line 90. As the relatively cool air CA fromevaporator 82 flows acrosscondenser 86, the refrigerant is cooled and its temperature is lowered as heat is transferred to the air for supply tochamber 25 ofdrum 26. - Upon exiting
condenser 86, the refrigerant is fed throughrefrigerant line 90 toexpansion valve 88.Expansion valve 88 lowers the pressure of the refrigerant and controls the amount of refrigerant that is allowed to enter theevaporator 82. The flow of liquid refrigerant intoevaporator 82 is limited byexpansion valve 88 in order to keep the pressure low and allow expansion of the refrigerant back into the gas phase inevaporator 82. The evaporation of the refrigerant inevaporator 82 converts the refrigerant from its liquid-dominated phase to a gas phase while cooling and drying the moisture laden air MLA received fromchamber 25 ofdrum 26. The process is repeated as air is circulated along processair flow path 58 while the refrigerant is cycled through sealedsystem 80, as described above. Althoughdryer appliance 10 is depicted and described herein as a heat pump dryer appliance, in at least some embodiments,dryer appliance 10 can be a combination washer/dryer appliance as previously stated. - For this exemplary embodiment, the
electronic expansion valve 88 can be operable to adjust a pressure of the refrigerant flowing along sealedsystem 80. For example,controller 56 may be configured to cause theelectronic expansion valve 88 to adjust the pressure of the refrigerant flowing along the sealedsystem 80. For instance, theelectronic expansion valve 88 can be moved from a first position to a second position which is a closed position or an intermediate position (e.g., not fully open or fully closed) which is closer to the closed position than the first position. This can increase the pressure on the high side of sealedsystem 80 and decrease the pressure on the low side of sealedsystem 80. Accordingly, the temperature of the refrigerant increases on the high side of sealedsystem 80 and the temperature of the refrigerant decreases on the low side of sealedsystem 80. That is, adjustment of the electronic expansion valve can drive higher temperatures incondenser 86 and can lower the temperature of theevaporator 82. - Further, adjustment of the
electronic expansion valve 88 can maintain a constant superheat in the sealedsystem 80 and in particular a constant level of superheat into thecompressor 84, such as to avoid liquid refrigerant reaching thecompressor 84. For example, thecontroller 56 may be configured to automatically adjust theelectronic expansion valve 88 to maintain a constant degree of superheat into thecompressor 84. As the degree of superheat in the sealedsystem 80 decreases, e.g., when the remaining moisture content in the laundry articles LA is below a certain level or threshold, theelectronic expansion valve 88 may be closed (or partially closed, e.g., moved to an intermediate position which is closer to the closed position than a prior position) to restrict the flow of refrigerant in the sealedsystem 80. Thus, in some embodiments, the degree of superheat in the sealedsystem 80 and therefore the dryness of the laundry articles LA may be determined based on the position of theelectronic expansion valve 88. For example, thelaundry appliance 10 may include a position sensor or other expansion valve position tracking system which may be used to determine the position of theelectronic expansion valve 88 and thereby determine or detect dryness of the laundry articles LA based on the position of theelectronic expansion valve 88. - As shown,
appliance 10 may include one or more lint filters 46 and 110 to collect lint during drying operations. By way of example,lint filter 46 is readily accessible by a user of the appliance. As such,lint filter 46 should be manually cleaned by removal of the filter, pulling or wiping away accumulated lint, and then replacing thefilter 46 for subsequent drying cycles. Alternatively, or in addition tolint filter 46,appliance 10 may include one or more of an auto-cleaninglint filter 110 that is automatically cleaned at certain times as part of the operation ofappliance 10. Each of thesefilters path 58 of air flow throughappliance 10 and includes a screen, mesh, other material to capture lint in the air flow. The location of lint filters inappliance 10 as shown inFIG. 3 is provided by way of example only, and other locations may be used as well. - With continued reference to
FIG. 3 ,appliance 10 may include temperature sensors and relative humidity sensors that provide temperature (e.g., dry bulb temperature) and humidity measurements tocontroller 56 from certain locations in the air flow alongpath 58 during a drying cycle. More particularly,appliance 10 includes atemperature sensor 104 and arelative humidity sensor 105 placed at theoutlet 54 of drum 26 (havingcompartment 25 for receipt of a load of articles for drying) in order to measure the temperature and relative humidity of theair exiting drum 26. Such air is received fromcompartment 25 and may be MLA or moisture laden air, particularly in the earlier time period of a drying cycle of wet laundry articles. In this embodiment, in terms of the air flow alongpath 58,temperature sensor 104 andrelative humidity sensor 105 are downstream ofdrum 26 and upstream ofevaporator 82. Based on their location relative to drum 26 and the direction of air flow,temperature sensor 104 andrelative humidity sensor 105 may also be referred to herein as the drum outletair temperature sensor 104 and drum outlet airrelative humidity sensor 105. -
Appliance 10 also includes atemperature sensor 106 and arelative humidity sensor 107 placed upstream of thedrum 26 and at theoutlet 87 ofcondenser 86 to measure the temperature and relative humidity of the after treatment bycondenser 86 and before enteringdrum 26. Such air is supplied tocompartment 25 and may be DA or relatively dry air from which water vapor has been removed as previously described. Based on their location relative to drum 26 and the direction of air flow,temperature sensor 106 andrelative humidity sensor 107 may also be referred to herein as the condenser airoutlet temperature sensor 106 and the condenser air outletrelative humidity sensor 107. - As an alternative, or in addition thereto,
appliance 10 may include another placement of a temperature sensor and/or relative humidity sensor for measurements of air that is suppled tocompartment 25—placement that is downstream ofcondenser 86 and located just before enteringdrum 26. As shown inFIG. 3 ,appliance 10 may include atemperature sensor 108 and relative humidity sensor 109 placed at theinlet 52 ofdrum 26. Based on their location relative to drum 26 and the direction of air flow,temperature sensor 108 and relative humidity sensor 109 may also be referred to herein as the drum inletair temperature sensor 108 and drum inlet air relative humidity sensor 109. - Other locations for both
temperature sensors relative humidity sensors compartment 25 ofdrum 26. -
Appliance 10 may also include means for determining the average moisture extraction rate (MER) from a load of laundry articles place in thecompartment 25 ofdrum 26 during a drying cycle. The average moisture extraction rate or MER will be understood as the average rate of removal of moisture from articles indrum 26 by the air circulated therethrough during a drying cycle. For example,appliance 10 may include aload sensor 110 ondrum 26. Load sensor can measure the weight w of laundry articles place indrum 26 at certain times t over the course of a drying cycle and provide this information tocontroller 56. As moisture is removed from the laundry articles during the drying cycle, the weight of laundry articles indrum 26 will decrease. This is illustrated inFIG. 4 , which depicts the weight w of a laundry load indrum 26 over time t during a drying cycle forappliance 10.Controller 56 can calculate an average MER by dividing the change in weight of the laundry articles by the elapsed time during which such weight changed occurred, as represented by Equation 1: - Eq. 1—average MER
-
average MER=(w 2 −w 1)/(t 2 −t 1) - The average MER may, for example, be expressed as pounds of water per minute, kilograms per second, or other mass per time units that may be used as well. Notably, as shown in
FIG. 4 , the average MER (e.g., the slope of curve 103w) becomes relatively constant once steady state conditions are reached. - Alternatively, for determining an average MER, in another
exemplary aspect appliance 10 may use aflow meter 112 that measures the volumetric flow of condensate fromdrain line 92 and provides the same tocontroller 56. In still another exemplary aspect, condensate fromevaporator 82 may be collected in areservoir 116 and a pressure sensor or float 114 would measure the amount of condensate collected over a given time interval or determine when a predetermined amount of condensate has been collected inreservoir 116 and provide such information tocontroller 56. Using the teachings disclosed herein, one of skill in the art will understand that other techniques may also be used to determine the average MER. - As previously mentioned, filters 46 and/or 110 can accumulate lint and eventually create an undesirable pressure drop during operation of
appliance 10.FIG. 4 illustrates a plot during a drying cycle of the volumetric air flow rate in cubic feet per minute (CFM) throughair flow path 58.Plot 800 represents a lint filter that was about 25 percent blocked whereasplot 802 represents a lint filter that was about 75 percent blocked (the percentages were determined relative to the desired unblocked airflow, which was considered to be 100 percent). The volumetric air flow rate is higher for the less clogged filter represented byplot 800, and the volumetric air flow rate decreases over the time t of the drying cycle operation as lint accumulates. - For a laundry dryer such as
appliance 10 having aheat pump system 80 for providing heat to the drying air, the temperature of compressor 84 (as measured e.g., bytemperature sensor 91 will increase undesirably as the airflow is reduced by one or more clogged lint filters such asfilter 46 and/or 110. Once the temperature of the compressor exceeds a certain predetermined threshold, certain actions will be taken in response byappliance 10. The responses, referred to herein as “compressor temperature response” (CTR), can include one or more of a variety of actions depending upon the design ofappliance 10. As used herein, compressor temperature response or CTR means theaction appliance 10 undertakes in an effort to lower the temperature ofcompressor 84. The temperature of a compressor may be measured at the compressor's shell, which is simply a temperature measurement at an exterior wall or shell of the compressor. - For example, if
compressor 84 is a variable-speed type, then the compressor temperature response or CTR may include appliance 10 (e.g., controller 56) operatingcompressor 84 at a lower speed to maintain the superheated state and the inlet air temperature to drum 26. The lower compressor speed means the mass flow rate of refrigerant (as measured by e.g., meter 83) throughrefrigerant circuit 90 will decrease.FIG. 5 provides a plot of refrigerant mass flow rate over time as measured e.g., by refrigerant massflow rate sensor 83.Plot 900 representsappliance 10 having 25 percent filter blockage whereasplot 902 is forappliance 10 having a 75 percent filter blockage (the percentage being determined with respect to no lint present (0 percent) and total blockage (100 percent). As shown, the mass flow rate of refrigerant in either case first reaches a steady state condition during a drying cycle. Thereafter, the mass flow rate of refrigerant is significantly less forplot 902 where the lint filter(s) ofappliance 10 is significantly more clogged. In this example, the difference inplots - If
compressor 84 is a single-speed type, then compressor temperature response or CTR may includecontroller 56 activating an auxiliary condenser (connected in parallel or series with condenser 86) in order to maintain the superheated state and the inlet air temperature to drum 26. Alternatively, or in addition thereto, the compressor temperature response or CTR may includecontroller 56 activating a coolingfan 89 forcompressor 84 in order to maintain the superheated state and the inlet air temperature to drum 26.FIG. 6 provides plots of shell temperature ofcompressor 84 over time as measured by e.g.,temperature sensor 91.Plot 1000 is forappliance 10 having 25 percent filter blockage whereasplot 1002 is forappliance 10 having a 75 percent filter blockage (the percentage being determined with respect to no lint present (0 percent) and total blockage (100 percent). As shown, the compressor shell temperature fluctuates as e.g., coolingfan 89 is cycled on and off and/or as auxiliary condenser is employed in an effort to regulate the shell temperature ofcompressor 84. In addition, the frequency of the temperature regulation increases during a given drying cycle as lint accumulates in the filters(s), and the frequency of the temperature regulation is higher for the filter that is more clogged (plot 1002). As shown, the frequency of the temperature regulation by coolingfan 89 is about 50 percent higher when the filter(s) are 75 percent blocked as opposed to 25 percent blocked. Anappliance 10 with avariable speed compressor 84 may also be equipped to utilize an auxiliary condenser or cooling fan as an alternative, or in addition to, compressor speed control for purposes of compressor temperature response or CTR. - In one exemplary aspect, the present invention utilizes the compressor temperature response or CTR to determine the condition of the one or more lint filters in
air flow path 58. Based on the frequency of the compressor temperature regulation responses or CTRs, one or more actions may be undertaken bycontroller 56. Referring toFIG. 7 , an exemplary method of 200operating appliance 10 will now be described. Using the teachings disclosed herein, one of ordinary skill in the art will understand that other methods within the scope of the invention and claims that follow may be applied as well. - After
start 202 of a drying cycle forappliance 10, a determination is made instep 204 at a time after start-up of the drying cycle as to whether steady state conditions inappliance 10 have been reached. For this exemplary embodiment of the invention, determining steady state conditions may be important so that changes in the compressor temperature and/or mass flow rate of attributed to the accumulation of lint or clogging of the filter instead of being affected by transient changes that occur beforeappliance 10 reaches steady state. A variety of different techniques may be used to determine whetherappliance 10 has reached steady state conditions. - For example, during a drying cycle of
appliance 10 with a laundry load present incompartment 25 ofdrum 26,FIG. 8 depicts thetemperature measurements 108 T from drum inletair temperature sensor 108 andtemperature measurements 104T from drum outletair temperature sensor 104. For the same drying cycle asFIG. 8 ,FIG. 9 depicts the relative humidity (RH) measurements 109 RH from drum inlet air relative humidity sensor 109 and relative humidity (RH)measurements 105 RH from drum outlet airrelative humidity sensor 105. As shown inFIG. 8 ,temperature measurements 108T from drum inletair temperature sensor 108 changed rapidly during the first approximately 20 minutes of the drying cycle. The relative humidity measurements 109 RH from drum inlet air relative humidity sensor 109 also changed rapidly during the first approximately 10 minutes of the drying cycle. - One or both of the measurements depicted in
FIGS. 8 and 9 may be used byappliance 10, and specificallycontroller 56, to determine when steady conditions have been reached. For example,controller 56 may be configured to simply delay a predetermined period of time tinitial afterappliance 10 has been operating before proceeding to use compressor temperature response or CTR to determine the condition of the one or more lint filters inair flow path 58. In one embodiment, tinitial might be preset as 20 minutes, after which instep 202 thecontroller 56 proceeds under the assumption of steady-state conditions. Other time periods for tinitial may be used as well. - In another embodiment,
controller 56 would determine whether the rate of change (ROC) of thetemperature measurements 108 T, relative humidity measurements 109 RH, or both, has fallen below certain predetermined threshold values before proceeding to use compressor temperature response or CTR to determine the condition of the one or more lint filters inair flow path 58. As used herein, rate of change or ROC means the change in a measured value of a certain interval of time. For example, as indicative of a steady state condition being reached,controller 56 might monitor the temperature, relative humidity, or both, of air supplied to compartment or drum 26 to determine when the rate of change has reached or dropped below a predetermined threshold value, ROCTHR. In one embodiment,controller 56 may monitortemperature measurements 108 T and determine that a steady condition indrum 26 has not been reached until the rate of change (ROC) fortemperature measurements 108 T is less than an ROCTHR-T of 5 degrees per minute, less than 3 degrees per minute, or less than 1 degree per minute. Other values for ROCTHR may be used as well. - In still another example,
controller 56 may monitor relative humidity measurements 109RH and determine that a steady condition indrum 26 has not been reached until the rate of change (ROC) for relative humidity measurements 109 RH is less than an ROCTHR-RH of 10 percent per minute, less than 5 percent per minute, or less than 1 percent per minute. Other values for ROCTHR may be used as well. In still another embodiment,controller 56 might monitor both temperature and relative humidity measurements until the ROC for both thetemperature measurements 108T and relative humidity measurements 109RH are each below certain predetermined threshold values, ROCTHR. By way of further example,controller 56 might also use measurements fromsensors sensors 108 and 109. - In still another example,
controller 56 might also use measurements from refrigerant massflow rate sensor 83 to determine that steady state conditions have been reached before proceeding to use compressor temperature response or CTR to determine the condition of the one or more lint filters inair flow path 58. Accordingly,controller 56 might monitor the rate of change (ROC) for mass flow rate measurements and determine that steady conditions have not been reached until the ROC for the mass flow rate measurements is less than an ROCTHR-MF of 10 percent per minute, less than 5 percent per minute, or less than 1 percent per minute. Other values for ROCTHR-MF may be used as well. - At about the same time or shortly after steady state conditions are determined, in
step 206controller 56 ascertains whether the frequency of the CTRs (CTRF) is at, or exceeds, a predetermined frequency threshold (CTRF-THR) as an indicator of the conditions oflint filters 46 and/or 110. Returning toFIG. 6 , due to the shell temperature ofcompressor 84 repeatedly exceeding a certain temperature, appliance 10 (e.g., controller 56) has repeatedly initiated certain compressor temperature response or CTRs—such as activating coolingfan 89. Forplot 1002, where the lint filter(s) are 75 percent blocked, the frequency of CTRs has increased about 1.5 times over the 25 percent blocked condition depicted inplot 1000. - For example, CTRF-THR might be a fixed value such as CTRF-THR≥5 CTRs per hour or CTRF-THR≥10 CTRs per hour. Other values may be used as well. Alternatively,
controller 56 might determine CTRF-THR has been reached based on a predetermined amount of increase in the frequency of CTRs after reaching steady state conditions. For example,controller 56 might determine CTRF-THR has been reached if the frequency of CTRs increases by more than 50 percent. One of skill in the art will understand, using the teachings disclosed herein, that other methods for determining CTRF-THR may be used. - In the case of a variable speed compressor, if appliance 10 (e.g., controller 56) ascertains that the frequency of CTRs or CTRF-THR has met or exceeds a certain predetermined frequency threshold (CTRF-THR), then in
step 208appliance 10 proceeds to detect if the refrigerant mass flow rate (RMF), as may be measured by massflow rate sensor 83, is at or below a certain predetermined threshold value (RMFTHR). If so, thenappliance 10 can undertake one or more corrective actions. - In
step 210, for example, as acorrective action appliance 10 can provide a notification to the user that one or more filters need to be cleaned. In another exemplary embodiment, wherecompressor 84 is not a variable speed compressor, thenappliance 10 may skipstep 208 and proceed directly to undertaking one or more corrective actions such as providing a notification to the user as instep 210. Such alerts or notifications may be a visual and/or audible signal at the end of the previous drying cycle, could be provided when the user is about to initiate another drying cycle, or a combination thereof. - As will be understood by one of skill in the art using the teaching disclosed herein, other corrective actions may be utilized as alternatives, or in addition, to providing a notification (e.g., visual and/or audible) to the user. For example, if the frequency of CTRs or CTRF-THR has met or exceeds a certain predetermined frequency threshold (CTRF-THR) and/or the refrigerant mass flow rate (RMF) is at or below a certain predetermined threshold value (RMFTHR), then
appliance 10 may stop the current drying cycle ofappliance 10. If the frequency of CTRs or CTRF-THR has met or exceeds a certain predetermined frequency threshold (CTRF-THR) and/or the refrigerant mass flow rate (RMF) is at or below a certain predetermined threshold value (RMFTHR), thenappliance 10 may provide a notification to the user regarding a lint filter to indicate e.g., that such filter should be cleaned and/or stop operation ofappliance 10. If the frequency of CTRs or CTRF-THR has met or exceeds a certain predetermined frequency threshold (CTRF-THR) and/or the refrigerant mass flow rate (RMF) is at or below a certain predetermined threshold value (RMFTHR), thenappliance 10 may undertake an automated cleaning cycle of one or more lint filters. - Still other exemplary methods of
operating appliance 10 may be employed with the present invention as will be understood using the teaching disclosed herein. For example,appliance 10 may be equipped with anoversized lint filter 46 that does need to be cleaned with every drying cycle. Instead,appliance 10 and particularlycontroller 56 may be configured to estimate when lint filter cleaning will be needed depending on variables such as load types and sizes. The degradation of thefilter 46 can be correlated to the degree of filter loading for various load types and sizes, which can be determined based on user selection and load size determination as previously described. When a remaining interval for cleaning oflint filter 46 is less than a certain threshold value,appliance 10 can alert the user that one or more lint filters or e.g.,lint filter 46 should be cleaned. Theprocess 200 described inFIG. 7 may be provided as a back-up to such estimations. - In still another example, CTRF-THR and/or RMFTHR may include a first set of predetermined values based on a lint filter that is only at e.g., 75 percent clogged so that the corrective action of
appliance 10 includes providing the user with a notification that the lint filter should be cleaned while continuing to allow operation ofappliance 10. A second set of values for CTRF-THR and/or RMFTHR (indicative of e.g., 90 percent clogging of the lint filter) might be used to initiate a subsequent corrective action where a drying cycle ofappliance 10 is terminated until the lint filter can be cleaned. Thus, if the first set of values for CTRF-THR and/or RMFTHR are reached, thencontroller 56 can provide an alert or notification to the user that the lint filter should be cleaned before starting another drying cycle, butcontroller 56 would only prevent another drying cycle if the second set of values for CTRF-THR and/or RMFTHR has been reached. - Accordingly, the process set forth in
FIG. 7 is exemplary and representative only. Using the description provided herein, one of ordinary skill in the art will understand that other steps may also be used within the scope of the invention and claims that follow. The order of certain steps may be changed and operations described or claimed as a single step herein may actually be executed in multiple steps or operations. The invention includes an appliance having one or more controllers, microprocessors and/or other elements configured to operate a drying appliance as previously described. Also, while exemplary aspects of the invention have been described using English units (e.g., in the equations above), such is by way of example only and one of skill in the art will understand that e.g., the International System of Units (SI) may be used as well. - This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2644246A (en) * | 1951-12-27 | 1953-07-07 | Gen Electric | Clothes drier lint trap |
US3325908A (en) * | 1965-01-07 | 1967-06-20 | Whirlpool Co | Dual function safety thermostat for dryers |
US6199300B1 (en) * | 2000-03-01 | 2001-03-13 | Whirlpool Corporation | Method for energy efficient control of a dryer of clothes |
US20180080169A1 (en) * | 2016-09-21 | 2018-03-22 | Lg Electronics Inc. | Control method for laundry drying machine |
KR20220033167A (en) * | 2020-09-09 | 2022-03-16 | 삼성전자주식회사 | Dryer and method for controlling the same |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DK167066B1 (en) | 1991-05-07 | 1993-08-23 | Nyborg Vaskerimaskiner As | DRUM TUMBLE WITH FNUG FILTER |
KR20030008647A (en) | 2001-07-19 | 2003-01-29 | 주식회사 엘지이아이 | Lint filter condition sensing apparatus for dryer |
KR100756446B1 (en) | 2001-07-24 | 2007-09-07 | 주식회사 엘지이아이 | Control method for lint filter |
KR100751132B1 (en) | 2006-10-02 | 2007-08-22 | 엘지전자 주식회사 | Controlling method for sensing filter blocking of dryer |
EP2333149B1 (en) | 2010-11-22 | 2013-11-06 | V-Zug AG | Tumble drier with ambient temperature sensor |
JP6918319B2 (en) | 2017-09-07 | 2021-08-11 | 日立グローバルライフソリューションズ株式会社 | Cloth drying device |
CN110093767B (en) | 2019-05-28 | 2020-05-19 | 珠海格力电器股份有限公司 | Heat pump clothes dryer filth blockage judging method and device and heat pump clothes dryer |
-
2021
- 2021-01-21 US US17/154,569 patent/US11846064B2/en active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2644246A (en) * | 1951-12-27 | 1953-07-07 | Gen Electric | Clothes drier lint trap |
US3325908A (en) * | 1965-01-07 | 1967-06-20 | Whirlpool Co | Dual function safety thermostat for dryers |
US6199300B1 (en) * | 2000-03-01 | 2001-03-13 | Whirlpool Corporation | Method for energy efficient control of a dryer of clothes |
US20180080169A1 (en) * | 2016-09-21 | 2018-03-22 | Lg Electronics Inc. | Control method for laundry drying machine |
KR20220033167A (en) * | 2020-09-09 | 2022-03-16 | 삼성전자주식회사 | Dryer and method for controlling the same |
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